Winches are in common use on sailboats for trimming and hoisting sails. The typical winch includes an over-running ratchet mechanism permitting rotation of the winch drum in one direction only, customarily clockwise. The usual practice in trimming a jib, for example, is to place one or two turns of the rope or line (on sailboats, called the sheet) that controls the angle of the sail, around the winch in a clockwise direction, pull on the free end of the rope to bring the rope into sufficient frictional engagement with the winch drum to hold the rope against the pull of the jib. Then while still holding the free end in tension with one hand, the operator commences rotation of the hand crank to wind the rope on the winch drum to the extent desired.
As the rope is wound on the winch, the free end of the rope, unwinding from the winch, must continue to be held in tension by the operator to maintain the necessary friction between the rope and drum. Failure to hold the unwinding free end of the rope in tension will cause the turns to become slack and the rope will slip.
Thus it will be understood that when the winch is operated by one person, both hands must be actively used, one hand turning the winch and the other keeping the free end of the rope in tension.
In situations where the load on the rope is so great that the operator must use both hands to turn the crank, then a second person is required to hold the free end in tension until the trimming of the sail is completed.
Upon completion of the trimming, the free end may continue to be held under tension if further sail adjustment is contemplated shortly or more usually the free end is temporarily secured to a cleat.